Help me with these 7 project tasks

[1978sierra]

Hey Guys,

I had another thread but it got jacked, and since then I have learned many a thing about my 78 C15. I have a list of things that I am trying to prioritize and am looking to this forum for help with the following. My truck is a 1978 GMC Sierra 15 3/4 tonne with a stock 305, 125000kms, at some point a mild cam was installed.

1. My quadrajet is pretty beat up I am having it rebuilt over Christmas. I will have to take it out myself, I have no idea how to do this. Currently, it's running ok but is running pretty rich to deal with the stall outs etc. I had a very reputable mechanic give me the rundown. His exact diagnosis was "carb in poor condition" - truck fires up well but wants to stall when I put it in gear until I gas it a bit, performance is poor until I can open it up.

2. I am leaking oil, not very much when sitting but seemingly more after driving around. I will replace the oil pan gasket, again I don't know if this is somethig I can do myself.

3. My temp guage reads 0 C at all times- I have no idea about this

4. My oil pressure is around 15psi all the time, does this seem low?

5. I need to replace the calipers up front as they don't return to open very well, I also need to replace the rear drum springs and the rear brake lines. Is this a DIY project?

6. My 'Fasten Belts' light is always on, however sometimes it'll flicker on and off for a bit before staying on, I have no idea why.

7. My wiper switch has 3 positions - Left is off, Middle is fast, right is off, push it in for fluid. I am assuming that there's a speed missing.7

For now I think that's it! I have a single car spot in an apartment building, so anything super complicated or needing a hoist I may have to farm out. Any advice on this stuff would be great. I should've paid more attention in mechanics class a kid, but this project is already one of the best things I have done for myself in years.

[mrolds88]

Everything you have listed can be a DIY project. You may want to get a manual. Either a factory one or a Chiltons. Obviously the factory manual is the most precise. One thing I may suggest for you too, is to take pics, lots if need be as you are disassembling anything. Several notes that I can think of. Temp sender may be bad. They are usually Driver side between front 2 plugs. Pull the green wire and ground it. If needle moves sender is bad. Oil leak. Are you sure it is the pan gasket? When it is sitting, where does the oil drip from? Does it drip while running and not when it is off? Brakes, Replace everything that looks suspect. At minimum on the front, put pads and calipers on. Don't forget the little copper washers that should be in with the calipers. Bleed calipers one at a time. will take 2 people. Pretty good video here. https://www.youtube.com/watch?v=GAE6i1Sd2S0

[PAWS 72]

Welcome to the board from way off down in Bama. You will get a lot of good info here from some knowlegedable people.

[TexasJeff]

I agree with MrOlds88, everything can be a DIY project. Great advice of pictures, that way once it is apart you have references on the way it should go back together. Carb removal is pretty basic, only 4 bolts, the hardest part is all the hoses and such that connect to the carb, (reason for pictures) and most oh the hoses will only fit one place, they have been there for years. Oil leak I would venture to say is the valve cover gaskets, then it runs down the block and to the oil pan. Fasten seat belt lamp sounds like it might be a ground problem, when the seat belt is installed it completes a circuit to turn the lamp off. The wiper switch has only 3 positions, off, low and high, and press for washer fluid, so that is working properly. Oil pressure may just be the gauge these are never very accurate, maybe add and after market gauge for better reading. Brake jobs, some advice, only do one side at a time, that way you can always go the other side for reference, especially on the rears, but a brake job is all very basic mechanics and will save you lots of money when most shops charge at least $100 an axle.

[slotard]

For the carb it almost sounds like low idle. I might try giving a quarter of a turn more idle speed, it might help.

Are emissions tested where you are? You might be better off with an aftermarket carb depending on what he's charging you.

[motornut]

Hi hows it goin?

I wouldn't bother to change from a Rodchester carb,try to fix it but they do wear out.Sometimes easier to start with a new/reman one if you can afford it.Could be the V covers or the back of the intake ,and check the oil sender back there.Check wire for seatbelt goes fusebox under the carpet,to the female part,I'd remove bulb.Check the wiper switch my 78 switch parts pushed out the back of itself.

[1978sierra]

Ok Guys,

Thanks for the help!

Here's a little background of what I've found / done so far.

Truck was running really rough in the cold, then one day after being parked outside in -3 wouldn't start. I figured I flooded it, but after some searching on this site I discovered it was my distributor. I pulled off the cap and cleaned it up and it fired right up. It's also running much better now.

I had a garage replace my oil pan gasket as it totally blew out and I just didn't have the time. Unfortunately it now has to go back to them as I am getting oozing oil at a few points on the new seal - Luckily they guarantee their work. The one thing I did find strange was that they said they had to use a longer bolt to install the new Fel-pro 1 piece gasket, but I didn't see that info anywhere on the Fel-pro site.

I looked into the temp sending unit, to my surprise (or not) there was no wire attached to the sending unit at all. I searched around and found a wire tied up to vac line by the distributor. I grounded that wire and it quickly made my gauge pin- So i hooked it up and........ nothing. So I'll go get a new sender today. I have included a pic of the wire and the sender for reference. I wonder why it would be detached and tied away like that. I also wonder how to fix the wire as it appears to be in poor condition. Besides giving me a temp reading the sender doesn't do anything correct?

My fasten belts light has miraculously just stopped working. So that's a bonus.

Only other thing someone might help me with. During heavy rainfall I get water coming through the firewall at the heater and pooling up on the floor. I don't want to put the floor back in until I can fix it. I'm just trying to figure out how it gets there in the first place and also how I can get to the leak area to seal it.

Thanks again for all your help guys!

Cheers,

[tucsonjwt]

Just my $.02 - brakes are not a job to do as a learning experience. If you have an experienced person working with you, then it may be a DIY task.

First step, take your truck to two different brake shops for a free brake check. Once you know what is wrong you can go online to Rock Auto and find out what the parts will cost. You might even be able to buy OEM AC Delco parts for cheap. If you need wheel cylinders, make sure that they are AC Delco. If your wheel cylinders leak in the future, you will lose your drums and shoes with brake fluid contamination. This has happened to me twice.

If you do decide to do the brakes yourself, take your truck to a brake shop when you are done and have them give you a free estimate. Tell them you just bought the truck and the previous owner said he had the brakes done, and you want to make sure they were done correctly. That way, if you made any mistakes, the brake shop can fix it without charging you for new parts, just labor to fix your error.

Since your truck is a 3/4 ton, you will likely have a floating rear axle and this will require more work than a 1/2 ton to replace the rear brakes.

[enaberif]

That sensor is the coolant sensor.. Should be a dark green wire on that side which should attach to it.

Leaking oil? Its a Gen1 SBC they all leak to some degree and can be slowed down without a lot of patience and time.

[Shugalou]

Tucson, good advice on telling the brake shop someone else did the hack job I'll be using that one once my brakes are wrapped up.

If you are looking for guidance on brakes check one of my posts I've had a heck of a time and highlighted some problems I had.

[Dead Parrot]

Quick test on your temp gauge is to ground the sender wire with the ignition on. The gauge should read way hot with the wire grounded. If not, either you have the wrong wire or your gauge or gauge wiring is bad. I have seen idle comp solenoid wires that were about the color of a temp wire and they aren't that far apart either.

On your short pan bolt issue, maybe a PO lost the original and used what he had around.

Another vote for replacing the valve cover gaskets. Replaced mine and went from 1 qt per 1000 miles to still full after 1300.

[tucsonjwt]

One tip on the valve cover gaskets - don't cheap out on this one.

Use metal core valve cover gaskets and spreader bars. The metal core gaskets will not squish down after time and the spreader bars will distribute the force of the cover bolts evenly. This reduces the chance for leaks.

Racers use heavy cast aluminum or steel valve covers which have the effect of "spreading" the force of the bolts to reduce leaking, but these are very pricey for good quality covers.

I got Magnum brand steel core gaskets but there are many other brands so you might want to research this. I got the spreader bars from Ebay for cheap.

[enaberif]

Use felpro blues for valve cover gaskets. Make 100% sure both surfaces are spotless and use a good cleaner.